There are many reasons valid educational reasons why specialty residents would rotate off service. Medicine is a very broad and very deep field with lots of subtleties within it. I am a specialist, but when a patient walks into my office with atypical chest pain, I need to ask why?
For example I treat lung cancer patients, daily. They often get chemotherapy as well. When a patient walks in and just plain looks sick, It might be anemia due to general medical illness, it might be the chemotherapy, or they might be internally bleeding. In one case like this, I had a patient in new onset (no prior history) Afib/Aflutter with symptomatic tachycardia, acutely hypotensive, and my time spent in torment on the acute medicine services prepared me to recognize this immediately, get the patient properly admitted to the proper service and stabilized quickly. Another case, a patient was placed on a corticosteroid to reduce edema in a brain tumor, and showed up in clinic severely dehydrated, despite drinking copiously. A few questions and a lab test showed that the steroid had pushed his blood sugars into the 600+ range and there was every indication he had previously undiagnosed diabetes well prior to his present diagnosis. Again the torment I went through on medicine service rotations prepared me for this event.
Likewise, when I have medicine residents rotate through my service, they learn what radiation mucositis is, why it happens and what we can do about it. They also learn that a head and neck cancer patient with Stage IVA disease is a very different situation than a lung cancer patient with Stage IV disease. They also learn that a patient with an esophageal cancer with a bleed can be stabilized with transfusions while a very quick course of radiation will shrink the cancer causing the bleed, in many cases, within a week, ending the need for transfusions and the patient will have a better quality of life. These are all reasons why we cross train, and why some specialties have to spend a rotating internship year.
So, be patient with those new to your floor, they mean well, they do have good intentions, they may not know that they do not know anything, but by the time they leave, they usually have a very good idea of what they need to do, and they training they received in med school will prepare them to understand what is going on in much more detail and depth, and much ore rapidly, and they will become much better doctors. And they will thank you (hopefully) for your patience and understanding, as you help them learn more of what they may need to know a long time from now in an office far, far away.
I think you've asked a very good question, and I know that sometimes off service residents (and the new interns) may seem quite ignorant of your floor protocols. I know I was. Medical school gives a brief taste of what residents/interns really learn when they are newly minted, and residency gives a much deeper and more specialized drink of their chosen specialty.
This is why we have internship/residency and why the training is so much longer, intense and in some cases, harsh. A physician must know not only his own specialty, but also enough of the others to know when to punt the patient to the next specialist, and how to advise that specialist from his own perspective.